License and Collaboration Agreements - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended						6 Months Ended
	Oct. 31, 2018	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
License And Collaboration Agreements [Line Items]
Contract with customer liability revenue recognized		$ 3,008,000		$ 4,539,000				$ 5,877,000	$ 9,993,000
Contract with customer liability		15,326,000	$ 18,334,000	35,308,000				15,326,000	35,308,000	$ 21,203,000	$ 39,747,000	$ 45,201,000
2017 License and Collaboration Agreement With Roche [Member] | Roche [Member]
License And Collaboration Agreements [Line Items]
Estimated costs to be incurred to satisfy performance obligation				100,000					300
Contract with customer liability revenue recognized		0		200				0	800,000
2018 License and Collaboration Agreement With Roche [Member]
License And Collaboration Agreements [Line Items]
Milestone payment receivable on exercise of option rights		100,000,000.0						100,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member]
License And Collaboration Agreements [Line Items]
Upfront payment received towards technology access fee	$ 45,000,000.0
Estimated costs to be incurred to satisfy performance obligation		0		0				0	0
Contract with customer liability current			6,100,000							12,000,000.0
Milestone payment receivable based on product		1,600,000						1,600,000
Milestone payment received			$ 3,000.0
Performance obligation revenue recognized		3,000,000.0		$ 4,300,000				5,900,000	$ 9,100,000
Contract with customer liability		15,300,000						15,300,000		$ 21,200,000
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Development Milestone [Member]
License And Collaboration Agreements [Line Items]
Milestone payment receivable based on product		217,000,000.0						217,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Development Milestone [Member] | First Patient Doosing Phase One Clinical Trial [Member]
License And Collaboration Agreements [Line Items]
Milestone payment received					$ 20,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Regulatory Milestone [Member]
License And Collaboration Agreements [Line Items]
Milestone payment receivable based on product		240,000,000.0						240,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Regulatory Milestone [Member] | Preclinical Data Submitted To FDA For Approval [Member]
License And Collaboration Agreements [Line Items]
Milestone payment received							$ 10,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Sales Milestone [Member]
License And Collaboration Agreements [Line Items]
Milestone payment receivable based on product		1,200,000,000						1,200,000,000
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | APC [Member]
License And Collaboration Agreements [Line Items]
Amount payable on exercise of option rights to use the license		15,000,000.0						15,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | TCL [Member]
License And Collaboration Agreements [Line Items]
Contract liabilities current reclassified to non current						$ 9,200,000
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Maximum [Member] | TCL [Member]
License And Collaboration Agreements [Line Items]
Amount payable on exercise of option rights to use the license		100,000,000.0						100,000,000.0
2018 License and Collaboration Agreement With Roche [Member] | Roche [Member] | Minimum [Member] | TCL [Member]
License And Collaboration Agreements [Line Items]
Amount payable on exercise of option rights to use the license		$ 50,000,000.0						$ 50,000,000.0